um: Implement a custom pte_same() function
authorRichard Weinberger <richard@nod.at>
Sat, 14 Apr 2012 15:29:30 +0000 (17:29 +0200)
committerBen Hutchings <ben@decadent.org.uk>
Wed, 30 May 2012 23:43:46 +0000 (00:43 +0100)
commite22b65022898e212f80ca989e613179e318b8a79
treecc7c84c59cc3e2be9b9cd9415c2229777944d80f
parent284f9201597d8be6378a76f7dedc9e8b318ced09
um: Implement a custom pte_same() function

commit f15b9000eb1d09bbaa4b0a6b2089d7e1f64e84b3 upstream.

UML uses the _PAGE_NEWPAGE flag to mark pages which are not jet
installed on the host side using mmap().
pte_same() has to ignore this flag, otherwise unuse_pte_range()
is unable to unuse the page because two identical
page tables entries with different _PAGE_NEWPAGE flags would not
match and swapoff() would never return.

Analyzed-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arch/um/include/asm/pgtable.h